As a special committee contemplates whether to continue adding fluoride to city drinking water, anti-fluoride advocates spoke Wednesday about the dangers of fluoride.
Four speakers presented a number of possible health problems and risks from fluoridation, using online videos.
The speakers repeated three points: Fluoride is only effective topically, is unsafe for babies and is the only cause of dental fluorosis (discoloration of the teeth).
They also cited a Centers for Disease Control and Prevention study that states 41 percent of children have dental fluorosis.
Last week, a pro-fluoride group also said that topical — or surface — application was the effective way of using fluoride and that there was no need to use fluoride for children without teeth.
The anti-fluoride speakers also stressed that the problem with adding fluoride is that although you can regulate the amount put into the water, you can’t monitor how much water people drink.
“You can’t control the dose; you can’t control who gets it,” said J. William Hirzy, retired senior scientist from the Office of Pesticides and Toxic Substances for the U.S. Environmental Protection Agency.
Hirzy said there never has been a random clinical study of the effects of fluoride on preventing tooth decay, one of the statements made that dentists in the audience seemed to agree with.
He said that using risk assessment science, no amount of fluoride is safe and doubted its ability to prevent tooth decay.
“You can’t get enough fluoride into the tooth enamel to make it acid resistant,” he said.
Hydrofluorosilicic acid, which is added to water, is a highly corrosive byproduct of fertilizer plants that is a pollutant, he said, but now has billions in sales for fluoridation and has a strong lobbying group.
Bill Osmunson, a San Diego dentist and anti-fluoride advocate, said by phone that tooth decay began to decrease before the introduction of fluoride in water and toothpaste.
A graph in a Powerpoint presentation showed the steady decline, and Osmunson said no one knows why it went down.
A number of dentists in the audience were skeptical, asking if studies had been reproduced or published in peer-reviewed publications and sometimes citing other studies from the same research facility that said the opposite.
The dentists also were wary about a study that showed a seven-point drop in IQ for children drinking fluoridated water in China, and they questioned whether other factors such as diet were considered.
Local documentary maker Gary Foreman said that Kentucky, where municipalities have 100 percent fluoridation, has the highest tooth loss rate in the country.
However, he and Hirzy knew of no studies that compared rural to urban rates in Kentucky or looked at other factors such as diet and genetics.